Extension boring-bit.



PATENTED. MAR. 10, 1903.

J. 0. BE YER. EXTENSION BORING BIT. APPLICATIDNTILED NOV. 13, 1902.

INVENTQR: [0 w I ATTORNEY.

UNITED STATES PATENT OFFICE.

JOHN G. BEYER, OF INDIANAPOLIS, INDIANA. v

EXTENSI'ON BORING-BIT.

SPECIFICATION forming part of Letters Patent No. 722,481, dated March IO, 1903.

Application filed November 13,1902. Serial No. 131,102. (No model.) 7

To all whom it may concern:

Be it known that 1, JOHN C. BEYER, a citizen of the United States, residing at Indianapolis, in the county of Marion and State of Indiana, have invented new and useful Improvements in Extension Boring-Bits; and I do declare the following to be a full, clear, and exact description of the invention, reference being had to the accompanying drawings, and to the letters of reference marked thereon, which form a part of this specification.

My invention relates to the class ofbits that are designed to be used for boring holes into wood, and it has reference particularly to the type of bits that maybe adjusted so as to bore holes of difierent sizes. 7

The object of the invention is to improve the construction of boring-bits, particularly the bit-head, the adjustable portion or blade of the bit, and the clamp for securing the blade to the bit-head thereof, so that the adjustable blade may be accurately gaged and firmly supported and also be quickly'adjusted without materially increasing the cost of production of the tools.

My invention consists in a bit-head having a recess therein, an adjustable blade, and a 1 combined blade-clamp and lover extending into the recess in the head; and the invention consists also in the novel parts and in the combination and arrangement of parts, as hereinafter particularly described and claimed.

Referring to the drawings, Figure 1 is a front elevation of a boring-bit constructed substantially in accordance with my invention, the central portion of the shank being broken away; Fig. 2, an end view of the bit; Fig. 3, a side view of a portion of a shank and bit-head and parts thereof, the main portions being shown in central section; Fig. 4, a front elevation of the bit-head and a portion of the shank; Fig. 5, a transverse sectional View on the line A A in Fig. 4:; Fig. 6, a rear plan View of the blade-clamp and lever, and Fig. 7 a side view of the blade-clamp and lever.

Similar reference characters in the drawings indicate like parts.

In construction the shank a maybe of the usual form, and it may be adapted to be held in the socket of a machine or in a brace, as desired. At the lower end of the shank is the bit-head b, the extremity of which has the 'is cut into the head b and of the lip f in a I nsual gimlet-point d and suitable fixed cutters.

The head I) is substantially semicylindrical, havinga flat front face e, against which the extensible blade B is secured. At the lower end of the face e, near the point (1, is a lip ffor guiding and retaining one edge of the blade B. At a suitable distance from the lip fare shoulders g g, projecting beyond the face e and facing toward the lip, the shoulders being preferably inclined. A recess 71 extends from the shoulders upwardly, its bottom being in substantially the same plane as the face e. A

screw-threaded bolt-hole iis provided, which extends from the face e into theihead b to receive the clamp-screw.

The bottom of the blade B has a-lipj at one edge thereof, adapted to engage the under side wedging manner. The opposite edge k of the blade B is beveled, and

preferably is provided with ribs Z, spaced equidistant-lyas, for instance, by thirty-seconds or by sixteenths of an inch apart. The front face of the blade has indicator-marks 'm, arranged as a scale to correspond with the ribs Z.

The clamp portion of the combined clamp and lever comprises a plateO, having shoulders n n, adapted to engage the shoulders g g, and the lever portion comprises an integral arm D, that fits neatly but freely in the recess h, the arm being bent or curved so that its end normally stands off from the bottom of the recess, the combined clamp and lover having a fulcrum-bearing about the pointof attachment of the two portions thereof. end 19 of the clamp portion opposite the shoulders n n is beveled and has grooves q, adapted to receive the ribs Z when the parts are assembled. The angles ofthe edge and the'end '9 are such that the end p extends over the edge It, soas to force the blade against the face e. A screw-bolt r is fitted into the hole i and may turn freely in a hole 3, provided in the clamp portion 0. The

length of the clamp-plate O is such that when forced into contact with the blade B the under side y, near the blade, will clear the face e, and about t the combined clamp' and lever will find a bearing against the face 6, the wedging pressure of the clamp portion against the blade being resisted by the shoulders at The the opposite end of the clamp portion. The front face of the clamp and lever is hollowed out, as at u, to clear the borings. The front face at the end 19 of the plate 0 has a zeromark 1), to which the marks m may be set in gaging the blade B, so as to bore different ter may be moved endwise to any desired position. Then the clamp portion may be pressed down by hand, While the screw may be tightened as before. The bit may be used in the same manner as others of the same character.

Having thus described my invention, what I claim is- 1. A boring-bit comprising a bit-head and a movable bit-blade provided with a combined clamp and lever fulcrumed intermediately of'its ends against the bit-head and engaging the bit-blade, and means whereby the combined clamp and lever may be secured to the bit-head and forced against the bit-blade.

2. A boring-bit comprising a bit-head having an extended recess therein adapted to receive an arm of a lever, a movable bit-blade mounted in the bit-head, a combined clamp and lever having a fulcrum on the bit-head and engaging the bit-blade and having an arm extending into the recess divergently from the bottom thereof, and means whereby the combined clamp and lever may be secured to the bit-head and also forced into engagement with the bit-blade.

3. In a boring-bit, the combination with the bit-head, and transversely-movable bitblade having positive locking devices, of a combined clamp and lever having one end thereof provided with locking devices en gaging the locking devices of the bit-blade and the other end thereof diverging from the bithead, the combined clamp and lever having a fulcrum-bearing intermediately of its ends, and the clamp-screw situated intermediately of the fulcrum-bearing and the locking devices of the clamp, substantially as set forth.

4. In a boring-bit, the combination of the bit-head having the inclined shoulders, the bit-blade having the ribs at the edge thereof, a combined clamp and lever havingafulcrum on said bit-head and having the inclined shoulders engaging the shoulders of the bithead and also having the grooves receiving said ribs and locking said blade, the clampscrew forcing said grooves over said ribs, said bit-head having the extended recess receiving an arm of said clamp and lever, and the extremity of said arm diverging from the bottom of said recess, substantially as set forth.

In testimony whereof I affix my signature in presence of two witnesses.

JOHN C. BEYER.

Witnesses:

WM. H. PAYNE, E. T. SILvIus. 

